<span>energy provided=13.4 eV
energy released=0.7 eV
energy absorbed = 12.7eV
initial energy= -13.6eV [ground state]
final energy = -13.6+12.7 = -0.9 eV
This energy corresponds to n=4 in hydrogen atom</span>
The crackling sound Is mainly to do with chemistry, The fireworks are filled with lead oxide, which turns into lead atoms as the firework explodes and heat up—— whistling sounds, the whistle is down to the tube being narrow one, thus rockets make a whistling noise


In the above equation, the product formed is :

_____________________________

Answer:
The frequencies of the two lines are:
a) 
b)
When we heat rubidium compound we will see red color.
Explanation:

c = speed of light
= wavelength of light
a) Frequency of the light when wavelength is equal to 



This frequency corresponds to red light
b) Frequency of the light when wavelength is equal to 



This frequency corresponds to violet light
When we heat rubidium compound we will see red color.